As one of the semiconductor manufacturing processes, there is a plasma process such as an etching process, a film forming process or the like which uses plasma of a processing gas. For example, in a single-subatrate plasma processing apparatus, it is required to properly control the plasma density distribution to become appropriate in a plane direction of a substrate depening on a process type, specifically based on a structure in a processing chamber, or in consideration of in-plane deviation of the substrate plane in a post-porcess. Therefore, the requirement is not limited to making the plasma density distribution uniform in an entire plane of the substrate and may include making the plasma density distribution different between a central portion and a periphery portion of the substrate.
As one of the plasma generating method in the plasma processing apparatus, there is a method in which, e.g., a high frequency power is supplied to an antenna and an induced electric field is generated in a processing chamber to excite a processing gas. For example, Japanese Patent Application Publication No. 5227245 (paragraphs [0055]-[0062], FIGS. 3 to 6) discloses a configuration in which a coil-shaped inner antenna and a coil-shaped outer antenna formed concentric to the inner antenna are provided as a high frequency antenna which outputs a high frequency, and each of the antennas resonates at a frequency of ½ wavelength of the high frequency. In this plasma processing apparatus, a circular electric field is each formed by each antenna, and thus in-plane distribution of the plasma density can be very delicately adjusted. However, a high frequency power supply needs to be provided at each of the inner antenna and the outer antenna.